This invention relates to methods and apparatus for determining whether or not an image is substantially like other images.
Although the principles of this invention are equally applicable in other contexts, the invention will be fully understood from the following explanation of its use in the context of product image inspection.
Many products such as packaged foods and beverages, cleaning products, paper products, smoking articles, and the like are produced in such large quantities and at such high speeds that some form of automated image inspection is required if the appearance of the product is to be inspected. Such inspection is important because the product may not be saleable if its appearance is defective. In addition, the inspection system should promptly alert those in charge of production if an excessive number of defective-looking products are being produced. If possible, the inspection system should be able to advise those in charge of production where in the image the defect causing rejection is in order to assist in the formulation of corrective action.
Many prior art image inspection systems inspect only predetermined portions of an image. This has at least two important drawbacks. First, setting up such systems typically requires large amounts of highly skilled operator time, and this process may have to be repeated each time the product to be inspected changes. Second, the system may not detect defects of unexpected kinds or defects in unexpected places.
In view of the foregoing, it is an object of this invention to provide improved image inspection methods and apparatus.
It is a more particular object of this invention to provide image inspection methods and apparatus which can inspect all portions of an image if desired.
It is another more particular object of this invention to provide image inspection methods and apparatus which can set themselves up to perform image inspections by gathering data from samples of the images to be inspected.